/*
* Copyright (C) 2010-2016 JPEXS, All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3.0 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library.
*/
package com.jpexs.helpers;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;
import java.util.concurrent.RunnableFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
*
* @author JPEXS
* @param <T>
*/
public abstract class CancellableWorker<T> implements RunnableFuture<T> {
private static final ExecutorService THREAD_POOL = Executors.newCachedThreadPool();
private static List<CancellableWorker> workers = Collections.synchronizedList(new ArrayList<CancellableWorker>());
private final FutureTask<T> future;
public CancellableWorker() {
super();
Callable<T> callable = new Callable<T>() {
@Override
public T call() throws Exception {
return doInBackground();
}
};
future = new FutureTask<T>(callable) {
@Override
protected void done() {
workerDone();
}
};
}
protected abstract T doInBackground() throws Exception;
@Override
public final void run() {
workers.add(this);
future.run();
}
protected void onStart() {
}
protected void done() {
}
public final void execute() {
onStart();
THREAD_POOL.execute(this);
}
@Override
public final boolean cancel(boolean mayInterruptIfRunning) {
boolean r = future.cancel(mayInterruptIfRunning);
if (r) {
workerCancelled();
}
return r;
}
public void workerCancelled() {
}
@Override
public final boolean isCancelled() {
return future.isCancelled();
}
@Override
public final boolean isDone() {
return future.isDone();
}
@Override
public final T get() throws InterruptedException, ExecutionException {
return future.get();
}
@Override
public final T get(long timeout, TimeUnit unit) throws InterruptedException,
ExecutionException, TimeoutException {
return future.get(timeout, unit);
}
private void workerDone() {
workers.remove(this);
done();
}
public static <T> T call(final Callable<T> c, long timeout, TimeUnit timeUnit) throws InterruptedException, ExecutionException, TimeoutException {
CancellableWorker<T> worker = new CancellableWorker<T>() {
@Override
protected T doInBackground() throws Exception {
return c.call();
}
};
try {
worker.execute();
return worker.get(timeout, timeUnit);
} finally {
worker.cancel(true);
}
}
public static void cancelBackgroundThreads() {
List<CancellableWorker> oldWorkers = workers;
workers = Collections.synchronizedList(new ArrayList<CancellableWorker>());
for (CancellableWorker worker : oldWorkers) {
if (worker != null) {
worker.cancel(true);
} else {
Logger.getLogger(CancellableWorker.class.getName()).log(Level.SEVERE, "worker is null");
}
}
}
}